Showcase: nutils: Utilities for Nu

[dch82]

Hello,

I just wanted to showcase my ongoing project, nutils. It's a collection of utilities and wrappers to replace programs provided by traditional POSIX-compatible utility libraries.

So far I have:

• df: Basic functionality and --all flag.

Output

╭───┬────────────────┬───────────┬───────────┬───────────┬─────────┬────────────────╮
│ # │   filesystem   │   size    │   used    │   avail   │  used%  │   mountpoint   │
├───┼────────────────┼───────────┼───────────┼───────────┼─────────┼────────────────┤
│ 0 │ devtmpfs       │ 791.7 MiB │       0 B │ 791.7 MiB │       0 │ /dev           │
│ 1 │ tmpfs          │   7.7 GiB │  76.5 MiB │   7.7 GiB │  0.9668 │ /dev/shm       │
│ 2 │ tmpfs          │   3.9 GiB │   7.3 MiB │   3.9 GiB │  0.1839 │ /run           │
│ 3 │ tmpfs          │   7.7 GiB │ 408.0 KiB │   7.7 GiB │  0.0050 │ /run/wrappers  │
│ 4 │ none           │   2.0 GiB │  83.3 MiB │   1.9 GiB │  4.0678 │ /              │
│ 5 │ /dev/nvme0n1p2 │ 476.4 GiB │  25.9 GiB │ 450.5 GiB │  5.4462 │ /nix           │
│ 6 │ /dev/nvme0n1p1 │ 510.7 MiB │  82.7 MiB │ 428.0 MiB │ 16.1978 │ /boot/efi      │
│ 7 │ tmpfs          │   1.5 GiB │  96.0 KiB │   1.5 GiB │  0.0059 │ /run/user/1000 │
╰───┴────────────────┴───────────┴───────────┴───────────┴─────────┴────────────────╯

• lsr: A replacement to tree and ls -r which displays in recursive tables.

Output

╭───┬────────────────┬────────────────────────────────────╮
│ # │      name      │              contents              │
├───┼────────────────┼────────────────────────────────────┤
│ 0 │ nixos-inserter │ ╭───┬────────────────┬──────────╮  │
│   │                │ │ # │      name      │ contents │  │
│   │                │ ├───┼────────────────┼──────────┤  │
│   │                │ │ 0 │ LICENSE        │    ❎    │  │
│   │                │ │ 1 │ README.md      │    ❎    │  │
│   │                │ │ 2 │ nixos-inserter │    ❎    │  │
│   │                │ ╰───┴────────────────┴──────────╯  │
│ 1 │ nutils         │ ╭───┬─────────────────┬──────────╮ │
│   │                │ │ # │      name       │ contents │ │
│   │                │ ├───┼─────────────────┼──────────┤ │
│   │                │ │ 0 │ CONTRIBUTING.md │    ❎    │ │
│   │                │ │ 1 │ LICENSE         │    ❎    │ │
│   │                │ │ 2 │ README.md       │    ❎    │ │
│   │                │ │ 3 │ nutils.nu       │    ❎    │ │
│   │                │ ╰───┴─────────────────┴──────────╯ │
╰───┴────────────────┴────────────────────────────────────╯

• who

Output

╭───┬───────┬───────┬───────────┬───────┬──────┬────────────────╮
│ # │ name  │  tty  │   date    │ idle  │ pid  │    comment     │
├───┼───────┼───────┼───────────┼───────┼──────┼────────────────┤
│ 0 │ dch82 │ seat0 │ a day ago │ ?     │ 2588 │ (login screen) │
│ 1 │ dch82 │ tty2  │ a day ago │ 18:47 │ 2588 │ (tty2)         │
╰───┴───────┴───────┴───────────┴───────┴──────┴────────────────╯

[fdncred]

Nice work on integrating nushell with other externals! The only thing that I'd like to see different is to not use jc if possible. Here's are two different techniques on how to avoid it to make them more nushelly and not require people to have other externals.

Technique 1 - detect columns

❯ df -B1 |
   str replace "Mounted on" "Mountpoint" |
   detect columns |
   rename filesystem size used avail used% mountpoint |
   into filesize size used avail |
   upsert used% {|r| 100 * (1 - $r.avail / $r.size)}
╭───┬────────────────┬──────────┬──────────┬──────────┬───────┬────────────────────────────╮
│ # │   filesystem   │   size   │   used   │  avail   │ used% │         mountpoint         │
├───┼────────────────┼──────────┼──────────┼──────────┼───────┼────────────────────────────┤
│ 0 │ /dev/disk3s1s1 │ 994.7 GB │ 455.1 GB │ 539.6 GB │ 45.75 │ /                          │
│ 1 │ /dev/disk3s6   │ 994.7 GB │ 455.1 GB │ 539.6 GB │ 45.75 │ /System/Volumes/VM         │
│ 2 │ /dev/disk3s2   │ 994.7 GB │ 455.1 GB │ 539.6 GB │ 45.75 │ /System/Volumes/Preboot    │
│ 3 │ /dev/disk3s4   │ 994.7 GB │ 455.1 GB │ 539.6 GB │ 45.75 │ /System/Volumes/Update     │
│ 4 │ /dev/disk1s2   │ 524.3 MB │  20.5 MB │ 503.7 MB │  3.92 │ /System/Volumes/xarts      │
│ 5 │ /dev/disk1s1   │ 524.3 MB │  20.5 MB │ 503.7 MB │  3.92 │ /System/Volumes/iSCPreboot │
│ 6 │ /dev/disk1s3   │ 524.3 MB │  20.5 MB │ 503.7 MB │  3.92 │ /System/Volumes/Hardware   │
├───┼────────────────┼──────────┼──────────┼──────────┼───────┼────────────────────────────┤
│ # │   filesystem   │   size   │   used   │  avail   │ used% │         mountpoint         │
╰───┴────────────────┴──────────┴──────────┴──────────┴───────┴────────────────────────────╯

Technique 2 - parse

❯ who -u | parse '{user}  {tty}      {datetime}  {idle}          {pid}' | update datetime {|r| $r.datetime | into datetime}
╭───┬─────────┬─────────┬────────────┬──────┬─────╮
│ # │  user   │   tty   │  datetime  │ idle │ pid │
├───┼─────────┼─────────┼────────────┼──────┼─────┤
│ 0 │ fdncred │ console │ a week ago │ old  │ 170 │
│   │         │         │            │      │     │
╰───┴─────────┴─────────┴────────────┴──────┴─────╯

[dch82]

Also... Is it possible to implement these 2 commands in pure Nu?

[fdncred]

nushell doesn't have df atm, although we've toyed with adding it before. we may still. we don't have anything that works like who in nushell, that i know of. with lsr we can do du -a | table -e which approximates your tree output.

[dch82]

For unix-like systems, we could read from some special file to get results like who and df without external executables.

[fdncred]

ya, but then it's not cross-platform. we try really hard to be cross-platform at nushell.

[dch82]

I mean df and who aren't necessarily cross-platform... (*cough* *cough* Microsoft *cough*)

[fdncred]

I think coreutils has a df and who that may be cross-platform. I haven't tried them on Windows yet though.

[amtoine]

agree with @fdncred, i think your df and who can be written without external dependencies such as jc 😋

i have almost the same df as the one above, from my scripts

def df [] {
    ^df -h
        | str replace "Mounted on" "Mountpoint"
        | detect columns
        | rename filesystem size used avail used% mountpoint
        | into filesize size used avail
        | upsert used% {|it| 100 * (1 - $it.avail / $it.size)}
}

and for who, the command above returns an empty list to me 🤔
so i wrote the following

def who [] {
    ^who -u | str replace ' \s+' ',' --all | str trim | split column "," user tty datetime pid
}

which gives me

╭───┬─────────┬──────┬────────────────────────┬──────────╮
│ # │  user   │ tty  │        datetime        │   pid    │
├───┼─────────┼──────┼────────────────────────┼──────────┤
│ 0 │ amtoine │ tty1 │ 2023-07-23 10:01 00:19 │ 592 (:0) │
╰───┴─────────┴──────┴────────────────────────┴──────────╯

and with the fix in nushell/nushell#9775, you can even do

def who [] {
    ^who --all --heading --users | detect columns | rename name tty date idle pid comment exit | into datetime date
}

which gives

╭───┬─────────┬────────┬──────────────┬───────┬─────┬─────────┬──────╮
│ # │  name   │  tty   │     date     │ idle  │ pid │ comment │ exit │
├───┼─────────┼────────┼──────────────┼───────┼─────┼─────────┼──────┤
│ 0 │         │ system │ 16 hours ago │       │     │         │      │
│ 1 │ amtoine │        │ 16 hours ago │ 00:45 │ 0   │         │      │
│ 2 │ amtoine │ tty1   │ 16 hours ago │ 00:46 │ 627 │ (:0)    │      │
╰───┴─────────┴────────┴──────────────┴───────┴─────┴─────────┴──────╯

[dch82]

@amtoine @fdncred I implemented your oneliners into nutils!
BTW, if you have any ideas, just code it and submit a pr.

[dch82]

Does anybody have ideas for new commands?

[fdncred]

not at the moment. let's close this for now since it's not an issue. feel free to drop by our discord and discuss nushell scripting more.